The Garden Farm - the way to self-reliance

A Monthly Guide to Vegetable Gardening - July

Articles by Garden Expert John Harrison

Although the hectic sowing of the first part of the year is past, there are still things to sow, plant out and happily harvest. Those early potatoes should be coming out of the ground now and although they do not store as long as the maincrop varieties they will store until finished.

When you harvest your potatoes take care to remove all the tubers. Any left will not only sprout next year and become a weed but will also be a reservoir for disease and potato blight spores. It's often worth forking over a few days after harvesting potatoes because more seem to miraculously appear.

If the weather is dull and moist then there is a likelihood of potato blight striking. Apart from growing resistant varieties like the new Sarpo there are only two courses of action to take. First, trust to luck and hope it misses you which is not quite as silly as it sounds. In an average year it is very much a case of luck deciding. The second course of action is to use preventative sprays like the traditional Bordeaux mixture which is still approved for organic use despite the fact that copper is a poison and the non-organic Dithane is, in my opinion, better for the environment and the people eating the crop.

Keep an eye on the potatoes and if you spot characteristic brown blotched leaves remove that foliage immediately and incinerate. There is no cure for blight available to us and once started a spray may delay the inevitable but that is the best we can hope for.

Blight will also strike tomatoes, which seem to suffer more than potatoes. If moving from plot to greenhouse try to avoid spreading the disease by not handling blighted foliage and then going into the greenhouse. More often than not, the greenhouse crops will miss the blight.

For greenhouse crops and outdoor tomatoes where we demand a huge crop from the plants it is critical to keep feeding each week with a liquid fertiliser. Comfrey feed is as good as commercial tomato feed and free to produce.

It's a good idea to give your maincrop potatoes a feed as well. A major cause of poor crops with maincrop potatoes is that they run out of food. They are a very greedy plant and a boost now will pay a dividend in tubers. Tomato food is ideal for them, being part of the same family and watering between the rows with 10 litres per 3m of comfrey feed will do the job. If you don't have comfrey feed and don't want to spend on liquid tomato food then 50 to 100 grams of general fertiliser like fish, blood and bone or Growmore per square metre will provide the boost they need.

In the greenhouse watch the temperature and ensure good ventilation. It can get incredibly hot in a greenhouse with strong sun and scorch your plants. You should also consider shading the house either with blinds, films or with a shading wash